New generation of assistive systems for humans with disability: New tool for neurorehabilitation

In this paper we are discussing the “pacemakers” for cyclic and goal directed movements in humans with central nervous systems injury/disease that are based on electrical stimulation. The system that restores or augments movement is termed Motor Neural Prosthesis (MNP). The novelties needed to make MNP compatible with the richness of living systems must be based on better understanding of the effects of electrical stimulation to the complete neural network (peripheral and central nervous system) and the design that can mimic the operation of the natural system. The novelties that we are discussing are related to the following facts: 1) electrical stimulation activates both afferent and efferent pathways, 2) external (artificial) control should match the natural (biological) control, 3) sensors system needs to ensure the application of predictive automatic adaptation to perturbations from the target trajectories, and 4) systems should minimize nonphysiological effects of application of electrical stimulation leading to tissue changes and fatigue. Other issues that hinder the current applicability of MNP relate to the technical aspects (e.g., power source, connectors, miniaturization, biocompatibility), but they are more likely to be resolved in the nearest future due to fast development of micro and nano technologies.